#!/usr/bin/python3

"""

Set system language.

Sets the system language to the given `language`, which must be a valid locale

identifier, like "en_US.UTF-8".

Removes `/etc/locale.conf` and then uses `systemd-firstboot` from the buildhost,

with the `--locale` flag, which will write a new `/etc/locale.conf` in the

target system with `LANG={language}`.

"""

import json

import subprocess

import sys

import os

SCHEMA = """

"additionalProperties": false,

"required": ["language"],

"properties": {

  "language": {

    "type": "string",

    "description": "Locale identifier (like 'en_US.UTF-8') for system LANG"

  }

}

"""

def main(tree, options):

    language = options["language"]

    # We need to remove the /etc/locale.conf file first, because it is created while we install RPM packages.

    # systemd-firstboot expects that if /etc/locale.conf exists it is a user-defined value and does not change it, but

    # the assumption is wrong, because it contains a default value from RPM package.

    try:

        os.remove(f"{tree}/etc/locale.conf")

        print("/etc/locale.conf already exists. Replacing.")

    except FileNotFoundError:

        pass

    subprocess.run(["systemd-firstboot", f"--root={tree}", f"--locale={language}"], check=True)

if __name__ == '__main__':

    args = json.load(sys.stdin)

    r = main(args["tree"], args["options"])

    sys.exit(r)